When a kasrah precedes Allāh, its lām is light. The clear examples are بِاللّٰهِ and لِلّٰهِ.
Contrast وَاللّٰهِ (heavy lām) with بِاللّٰهِ (light lām). This contrast concerns phonetics, not the reverence due to the name. The immediately preceding vowel determines the treatment in connected recitation.
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Allāh: kasrah before it gives light lām
Tafkhīm and Tarqīq — Alif, Divine-Name Lām and Rāʾ
When a kasrah precedes Allāh, its lām is light. The clear examples are بِاللّٰهِ and لِلّٰهِ.
Contrast وَاللّٰهِ (heavy lām) with بِاللّٰهِ (light lām). This contrast concerns phonetics, not the reverence due to the name. The immediately preceding vowel determines the treatment in connected recitation.